The ever-increasing amount of airbag equipment in vehicles has allowed a great deal of information to be gathered concerning the operation of airbags, something which has greatly contributed to improving them. One of these improvements consists in subjecting the operation of the airbag to an intelligent control unit which may be fed by various detectors in order to adapt the deployment of the airbag to certain circumstances.
Thus, for example, document DE-4237072 proposes a system for detecting whether or not the passenger seat is occupied, so as to disable this airbag when this seat is not occupied, in order not to have to replace the airbag when the vehicle is repairable after an impact which has triggered the deployment of the airbag.
Furthermore, novel gas generators are currently under development so as to make it possible, in the future, to have a multi-level operation and a deployment which is modulated and more graduated than all-or-nothing, especially so as to take account of the inertial mass of the passenger, which may be obtained through the information supplied by the seat-occupancy detector, when the latter consists of a pressure sensor of the FSR type.
Moreover, equipping each seat of a vehicle with several individual airbags, the deployments of which are different and adapted to zones to be protected is known.
Although the merit of airbags has meanwhile been recognized in the interest of passenger safety, there are, however, situations in which the deployment of an airbag may be harmful, or even constitute serious danger. There are currently on the market many types of auxiliary child or infant seats which are designed to be installed on the front passenger seat. Of these seats, some are designed to point in the direction of travel of the vehicle, and others in the opposite direction with the back against the glovebox area or the dashboard and some may be installed either way round as desired.
Now, for most seats which point in the opposite direction to the direction of travel of the vehicle, there is the risk that the deployment of the airbag will throw the child together with the seat violently towards the rear of the vehicle and will be the cause of serious injury. In such a case, and for the seats in question, it would therefore be useful to be able to disable the airbag.
It has even been observed that some child seats which point in the direction of travel may also be dangerous in the event of the deployment of the airbag, so that some manufacturers recommend that an airbag be disabled whenever the seat with which it is associated is occupied by an auxiliary child seat.
Moreover, sometimes the child seat remains in place on the seat of the vehicle without actually being occupied. In this case, there is also something to be said for avoiding the deployment of the airbag since, as mentioned earlier, the replacement of an airbag gives rise to quite substantial expenditure.